Fastener installation tools can utilise a supply of compressed air, which is supplied to the tool and subsequently routed through a central bore within the tool head piston in order to propel broken off fastener stems into a collecting bottle at the rear of the tool. Compressed air is also routed through a vacuum generator to create a vacuum to hold the fastener in place in the tool nosepiece prior to installation. When an external trigger is pressed, actuation means cause a head piston to be driven along a bore to cause a jaw-assembly to grip and pull a fastener stem which has been inserted into the tool nosepiece The trigger also causes an air valve to open and allow air to flow through the tool to propel the broken off stem into the bottle.
Prior to installing a fastener, there is often a need to apply a preload to the workpiece, to ensure that the fastener is correctly engaged with and aligned in the aperture into which it is being installed, therefore ensuring that the fastener will be installed correctly once the tool is actuated. A further advantage of applying a preload to a workpiece is that the application of sufficient force ensures that workpiece components are held together prior to installation of the fastener, therefore also ensuring a secure fastener installation.
Known methods of applying a preload to a workpiece into which a fastener is to be installed include the use of nose assemblies. Known nose assemblies tend to be large in diameter and/or bulky, therefore providing restricted access to the workpiece. Furthermore, adapters are required for both the tool and the piston rod.
It is an aim of the present invention to provide a standardised sensitive nose assembly which can be used for installation of various sizes of fastener and which can be fitted to an installation tool without the need for adapters.